organics testing Articles
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A single‐parameter logistic equation for fitting concentration‐response curves from standard acute ecotoxicity assays
A set of 69 concentration‐response (CR) curves from five acute ecotoxicity assays was fitted with a two‐parameter logistic equation. High correlation between values of regression parameters suggested similar slopes of the curves. This enabled derivation of the empirical single‐parameter logistic equation with the sole EC50 parameter. Such equation might be useful for evaluation of ...
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Criteria-Based Procedure for Selecting Test Methods for Effluent Testing and its Application to Toxkit Microbiotests
Abstract : In recent years there has been increasing development of methods (particularly rapid tests) for testing environmental samples. If appropriate methods are to be used for a particular operational role then it is necessary to adopt a robust and objective selection mechanism. This paper describes the application of a criteria-based procedure to the selection of test batteries of methods ...
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Aquatic toxicity of nanosilver colloids to different trophic organisms: Contributions of particles and free silver ion
The wide uses of nanosilver (nAg) have resulted in concerns regarding ecotoxicity to aquatic organisms. Some previous studies have found that the toxicity of nAg is due to the nanoparticles themselves, while others have found that ionic silver (Ag+) released by nAg particles plays an important role. In the present study, the authors quantitatively evaluated the relative contribution of nAg ...
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Organic fouling development in a long channel RO membrane cell
This study was to experimentally investigate organic fouling development in a 1-m long RO membrane channel using alginate as a model organic compound. Five parallel local permeate fluxes with a distance interval of 20 cm along the channel were monitored continuously during the organic filtration tests. It was found that organic fouling became more severe towards the outlet of the channel. This ...
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Macroinvertebrate responses to nickel in multi‐system exposures
Metals introduced to sediments undergo a variety of complexation and partitioning changes that affect metal bioavailability. We examined nickel (Ni) toxicity and bioavailability (simultaneously extracted metal (SEM)/acid volatile sulfide (AVS) and organic carbon (foc) models) in two field studies (using streamside mesocosm and in situ colonization) and one laboratory study. The streamside ...
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Juvenile zebrafish in the vitellogenin blank period as an alternative test organism for evaluation of estrogenic activity of chemicals
To determine the suitable development period of zebrafish for accurately evaluating estrogenic activities. An enzyme‐linked immunosorbent assay (ELISA) was developed and used to detect the Vtg‐derived yolk proteins and newly produced Vtg, and 9–56 d post‐hatching (dph) was determined as the Vtg‐blank period. Juveniles in this period was found to have lower baseline Vtg level than adult males ...
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Evaluating the aquatic toxicity of complex organic chemical mixtures: Lessons learned from polycyclic aromatic hydrocarbon and petroleum hydrocarbon case studies
Experimental designs for evaluating complex mixture toxicity in aquatic environments can be highly variable and, if not appropriate, can produce and have produced data that are difficult or impossible to interpret accurately. We build on and synthesize recent critical reviews of mixture toxicity using lessons learned from 4 case studies, ranging from binary to more complex mixtures of primarily ...
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Biological effects of contaminants on marine organisms: the contribution of biotechnology
One aspect of ecotoxicology concerns the effects of contaminants. Work on this area in the marine field is recent but useful for numerous applications, such as toxicological tests, the evaluation of organism response and the development of networks for the measurement of pollutant effects. In this context, the contribution of biotechnologies and technical advances in modern biology is important. ...
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A new approach based on polynomial functions for measuring the acute toxicity of environmental samples
In this paper, a new mathematical approach for the estimation of acute toxicity in environmental samples is proposed. The concentration of pollutant or the amount of sample producing the inhibition of 50% of the living organisms used for the test (EC50) is determined by means of Polynomial Functions (PF) applied to the experimental x (concentration of pollutant) and y (concentration or number of ...
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Toxicity of carbon nanotubes to freshwater aquatic invertebrates
Carbon nanotubes (CNTs) are hydrophobic in nature and thus tend to accumulate in sediments if released into aquatic environments. As part of our overall effort to examine the toxicity of carbon‐based nanomaterials to sediment‐dwelling invertebrates, we have evaluated the toxicity of different types of CNTs in 14‐d water‐only exposures to amphipods (Hyalella azteca), midges (Chironomus dilutus), ...
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Advancing the 3Rs in regulatory ecotoxicology: A pragmatic cross‐sector approach
The ecotoxicity testing of chemicals for prospective environmental safety assessment is an area where a high number of vertebrates are used across a variety of industry sectors. Refining, reducing and replacing the use of animals such as fish, birds and amphibians for this purpose addresses the ethical concerns and the increasing legislative requirements to consider alternative test methods. ...
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Bayesian approach to potency estimation for aquatic toxicology experiments when a toxicant affects both fecundity and survival
Chemicals in aquatic systems may impact a variety of endpoints including mortality, growth, or reproduction. Clearly, growth or reproduction will only be observed in organisms that survive. Because it is common to observe mortality in studies focusing on the reproduction of organisms, especially in higher concentration conditions, the resulting observed numbers of young become a mixture of zeroes ...
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Cyst-Based Toxicity Tests. - VI. : Toxkits and Fluotox Tests as Cost-Effective Tools for Routine Toxicity Screening
Abstract : During the last two decades microbiotests have been developed which are independent of recruitement, maintenance and/or culturing of live stocks of test organisms. Culture and maintenance free microbiotests have been worked out in the Laboratory for Biological Research in Aquatic Pollution at the University of Ghent, with selected aquatic invertebrates. The new approach is based on the ...
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Microbiological performance of novel household water treatment devices in India
Commercial innovation of household-scale water treatment (HWT) devices is rapid in India, where unsafe drinking water contributes to the high burden of disease and death associated with diarrhoeal diseases. Performance testing data for novel devices are not publicly available and there has been no systematic attempt to independently verify manufacturer effectiveness claims. We purchased three ...
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Acute toxicity and genotoxicity of five selected anionic and nonionic surfactants
The results of four toxicity bioassays of selected anionic and nonionic surface active agents were presented. Three widely used anionic surfactants that belong to alkyl sulphates (AS), alkylbenzene sulphonates (LAS) and alkylpolyoxyethylene sulphates (AES) as well as nonionic surfactants: polyoxyethylene alkyl ethers (AE) and polyoxylethylene alkylphenyl ethers (APE) were tested. Three different ...
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Effect of activated carbon or biochars on toxicity of different soils contaminated by mixture of native polycyclic aromatic hydrocarbons and heavy metals
Activated carbon (AC) and biochars (BCS and BCW) were added to the soils sampled from areas of strong anthropogenic influence at doses of 0.5, 1, 2.5 or 5% (w/w) and incubated for two months. At the end of this period, the toxicity of the soils was measured. The effect of AC and biochars on the toxicity of the soils varied based on soil, type of amendment, dose and test organism. For most of ...
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Characterizing the effects of bisphenol A on sediment dwelling benthic organisms
Bisphenol A (BPA) is a high production volume chemical intermediate used primarily in the production of polycarbonate plastics and epoxy resins. It primarily enters surface water and sediment via effluent discharges during its manufacture and use. The physical properties of BPA suggest that sediment is a potential sink and may result in exposure to benthic organisms. Currently there are no ...
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Sediment contact tests as a tool for the assessment of sediment quality in German waters
A sediment contact test (SCT) battery consisting of five ecotoxicological test systems was applied to 21 native freshwater sediments characterized by a broad variety of geochemical properties and anthropogenic contamination. Higher plants (Myriophyllum aquaticum), nematodes (Caenorhabditis elegans), oligochaetes (Lumbriculus variegatus), zebrafish embryos (Danio rerio), and bacteria ...
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Cyst-Based Toxicity Tests. - XII. Development Of A Short Chronic Sediment Toxicity Test With The Ostracod Crustacean Heterocypris incongruens. Selection Of Test Parameters
Abstract: Experiments have been carried out with neonates of the freshwater ostracod Heterocypris incongruenshatched from cysts, to develop a new culture/maintenance free solid phase microbiotest for toxicity assessment of contaminated sediments. Based on preliminary investigations, a number of test parameters were investigated for a short-chronic assay : the hatching time, the size of the test ...
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Limit Risk and Enhance Balance Testing Ease with New White Paper
Upgrade balance testing security and compliance with WeightLink, an innovative tracking system that assigns unique, scannable identifiers to each weight. Learn how quick weight identification and automated data gathering enhance balance testing by downloading our free white paper as part of METTLER TOLEDO's 2016 e-calendar. Adjustment and testing of lab balances can be an arduous task. ...
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